1. Technical Field
Example embodiments of the present invention relate in general to the field of wireless communication systems and methods of operating wireless communication systems, and more specifically, to a terminal device, a network device, and a method of operating a wireless communication system including both for adaptively reducing power consumption of the terminal device.
2. Related Art
Recently, in machine-to-machine (M2M) communication such as Smart Grid including general wireless communications, management and maintenance infrastructures for a terminal device which is used as a machine or sensor should be supported to operate in a reliable and efficient manner.
In most general sensor networks, however, it is difficult for the network to monitor real-time status information of a terminal device. The status information includes, but is not limited to, those indicating whether or not the terminal device is properly connected to a network in a state of on-line connectivity, whether the terminal device is accessible by a server at any time (also referred to as a reachability), whether the battery life of the terminal device is a sufficient, and so on. For this reason, a user is obligated to inform of the status information of the terminal device using separate communication means such as a telephone.
Therefore, it is necessary for a status information monitoring system in a network to predict and prevent any probable problems in the operation of a terminal device before the problems actually occur. To this end, the terminal device should periodically transmit a variety of status information including data information collected by the device itself to a network device. The terminal device need not always be powered on in order to transmit the status information to the network or receive instructions from the network, and thus terminal devices generally have a power saving system that periodically switches power modes, for example, the device periodically enters a low power mode but switches to a maximum power mode whenever power is required.
However, conventional power saving systems depend on a simple way to periodically switch a power mode into a low power mode, so that there is a problem with a lack of adaptability to situational changes.